Explanation of Underbet

The term “underbet” refers to any bet-sizing less than 50% of the pot.  Naturally the term is used mainly in describing games with a pot-limit or no-limit betting structure, since it would have no relevant application to a fixed-limit game.

Example of Underbet used in a sentence -> Underbets are a good way to try and extract thin value on the river.

How to Use Underbet as Part of Your Poker Strategy

The average player rarely or never underbets; they have been conditioned to always bet between 50% and 100% of the pot. This means they also rarely overbet – see the glossary entry under overbet.

Despite being rarely utilized, underbets are an important component of good strategy. The best players are not only willing to use such sizings but have decent ideas regarding when such sizings are incentivized. 

Here are some basic guidelines for different situations where underbetting might make sense in Hold’em (although the rules transfer to other variants in many cases) -

- Our hand is mediocre but vulnerable to being outdrawn. We hence want to protect our equity while avoiding over-investing in the pot. 

- Our opponent has a tendency to attack small bet-sizings and we can induce action with our premiums.

- We have a bluff/semi-bluff and our opponent’s folding range is inelastic. (I.e he will fold the same frequency regardless of the bet-sizing we use.

- We have a mid-strength made hand and our opponent’s range is polarized relative to us.

- We are looking to extract thin value. (This may not always apply when IP on the river since there are drawbacks associated with re-opening the action).

If we are currently never using underbet sizings in our game, there is a very good chance that we are not maximizing our potential winrate.

See Also 

Overbet, Bluff, Semi-Bluff, Vulnerable, Protection